Odor stabilization of sulfur-containing organic materials



ODOR STABILIZATION OF SULFUR-CONTAINING ORGANIC MATERIALS United StatesPatentfO Fredrick L. Jonach, Kew Gardens, N. Y., assignor to EssoResearch and Engineering Company, a corporation of Delaware No Drawing.Application September 22, 1955 Serial No. 536,013

5 Claims. (Cl. 260-139) This invention relates to the odor stabilizationof sulfur-containing organic materials which normally evolve hydrogensulfide and more particularly relates to a method for stabilizing suchmaterials by treating them with lead peroxide (PbO t0 the resultantstabilized products ing'eve'n small amounts of unstablesulfur-containing compounds will evolve hydrogen sulfide. Users of suchcompositions object to these odors and consequently the saleability ofthe product is impaired. Many organic compounds that have beensulfurized. or phosphosulfurized by treatment with sulfur, sulfides ofphosphorus and the like show this characteristic instability withrespect to hydrogen sulfide evolution. 7

Numerous attempts have been made in the prior art to stabilize suchsulfur-containing compounds or compositions including these compounds.None of these prior art methods have been entirely effective and theyhave been especially ineffective with pho-sphosulfurized hydrocarbonswhich in general are extremely potent H 8 evolvers. It is unfortunatethat heretofore it has not been possible to effectively stabilize thesephosphosulfurized hydrocarbons since not only are they inexpensive butthey are also among the most potent detergent and oxidation inhibitoradditives known for lubricating oil compositions.

It has now been found that the evolution of hydrogen sulfide fromunstable sulfur-containing organic materials may be effectivelyeliminated or at least partially reduced by treating these materialswith lead peroxide (PbO The lead peroxide treatment also reduces thecorrosivity of the sulfur-containing organic materials.

THE SULFUR-CONTAINING ORGANIC MATERIALS the sulfurized and/orphosphosulfurized hydrocarbons. These hydrocarbon materials maybeparafiins, such as bright stock residuums, lubricating oil distillates,petrola- 'tums, paraflin waxes, etc.; olefins, such as isobutylene,

P 3 P 8 P 8 or other phosphorus sulfide and is pref- 2,861,063 PatentedNov. 18, 1958 acrolein, decene, dodecene, cetene, octadecene,'etc.;olefin polymers having molecular weight ranges from about to 50,000,particularly from about 500 to l0,000, such as those of ethylene,propylene, butylene, isobut'ylene. amylenes, etc.; diolefins, such asbutadiene, isoprene, chloroprene, cyclopentadiene, terpenes', etc.;acetylenes; copolymers of low molecular weight monoolefins and diolefinshaving molecular weight ranges of about 1,000 to 30,000; aromatics, suchas-benzene, naphthalene,

'anthracene, toluene, xylene, diphenyl, etc.; alkyl aromatics; cyclicaliphatics; petroleum fractions; condensation products of halogenatedaliphatic hydrocarbons with an aromatic compound and'the like.

Another class of sulfur-containing organic compounds which are useful aslubricating oil additives are sulfurized and/or 'phosphosulfurizedoxygen-containing organic compounds. Included in this group aresulfurized and/ or phosphosulfurized animal and vegetable .oils, fats,rosins, resin and the acid ester hydrogenated and lower alkylderivatures thereof. Included in this class are products such assulfurized sperm oil, phosphorus sulfide treated ,rosin, rosinderivatives suchas methyl abietate and the like, for example, theproducts sold under the trade name Abalyn, Hercolyn and the like, aswell as various sulfur and/or phosphorus sulfide treated organic acids,

methyl esters, etc., derived from these products and fromlanolirndegras, tall oil, and the like. Such materials as have beendescribed above are well known to those skilled in the art.

The su'lfurization and/or phosphosulfnrization of hydrocarbons,oxygen-containing organic compounds and thelike are also well knownin'the art. Sulfurization is generally accomplished by reacting theorganic compound withelemental sulfur. The sulfides of phosphorus whichcan be employed for phosphosulfnrization include P 8 erably phosphoruspentasulfide (P 5 Mixtures of two or more phosphorus sulfides mayalsobe. employed as well as-mixtures of elemental phosphorus sulfur.

. The sulfurization and/ or phosphosulfurization reaction -isconveniently carriedout at an elevated temperature of about'200 to 600F., preferably about 300 to about 550 F., using in general about 2 toabout 5 molecular proportions of the organic compound to '1 molecularproportion of sulfur or phosphorus sulfide in the reaction. The-reactionwill generally be carried out until the maximum amount of sulfur orphosphorus sulfide has been added to the organic compound although thisis not essential. The reaction time is not'critical and the timerequired to cause the maximum amount of sulfur or phosphorus sulfide toreact will vary with the temperature. A reaction time of 2 to 10 hoursis frequently necessary and, if desired, the reaction product may befurther treated by blowing with steam, alcohol, ammonia, or an amine atan elevated temperature of about 200 F. to improve the odor thereofvto acertain extent. The sulfur-containing organicmaterials ofthis inventionwill generally contain at least 1.0% and usually at least 2.0% by weightof chemically combine-d sulfur. P 8 treated polyi'sobutylenes havingmolecular weights in the range of about 500 to 25,000, particularlyabout 500 to 2,000, are especially stabilized effectively in accordance'with this invenmaterials in accordance with this invention isaccomplished by treating these materials with lead peroxide -(PbO Ingeneral, the'unstable sulfur-containing organic materials will betreated with a small amountof Pb0 at an elevated temperature for anextended per od of time. In the stabilization reaction, the reactionvariables, namely, temperature, time and proportion of PbO areinterchangeable to a certain extent. Generally more effectivestabilization .will be'obtained when using higher temperatures, longerreaction times and greater proportions of P130:-

Elevated temperatures in the range of about 80 to 400 F. are generallyefiective in the stabilization reaction carried out in accordance withthe present inventon. Temperatures in the range of about 150 to 350 F.are ureferred and a temperature of about 300 F. has been shown to beexceedingly effective. As to the reaction time, generally a period of atleast about one hour is required. Effective stabilization is obtainedwhen utilizing reaction times of about 8 to 24 hours, preferably about12 to 16 hours. In general, about 0.5 to 50% by weight of PbOg will beemployed, based on the sulfurcontaining organic material to bestabilized. Proportions of PhD, in the range of about 5% to 30% byweight, based on the sulfur-containing organic material, are preferredand exceedingly effective results are obtained when utilizing about 10to 25% by weight of PbO If the sulfur-containing organic material isliquid under the treating conditions, the treating reaction may becarried out without a solvent. However, in general, it is preferred tocarry out the stabilization reaction of the present invention in thepresence of a solvent for the sulfur-containing organic material.Hydrocarbon solvents are preferred, with a mineral lubricating oil beingthe preferred solvent since normally the sulfur-containing organicmaterials useful as lubricating oil additives are marketed as additiveconcentrates consisting of the additive in a diluent mineral oil. Thestabilization reaction is preferably carried out with intimate mixing ofthe reactants, such as by stirring the reaction mixture. It is preferredto utilize PbO in a finely divided form (such as a powder) to provideready contact between it and the sulfur-containing organic materials.After the stabilization reaction, any unreacted PbO may be filtered fromthe reaction mixture. The stabilized reaction products of this inventionwill in general contain in the range of about 0.1 to 10 wt. of lead as aresult of the stabilization reaction.

The invention will be more fully understood by reference to thefollowing examples. It is pointed out, however, that the examples aregiven for the purpose of illustration only and are not to be construedas limiting the scope of the present invention in any way.

Example I The sulfur-containing organic material to be stabilized inaccordance with the present inventin.--A polyisobutylene of about 1100Staudinger molecular weight was reacted with about 10% by weight of P 8(based on the polyisobutylene) at a temperature of about 425 F. forabout 8 hours. The phosphosulfurized polyisobutylene was diluted with amineral lubricating oil to form two additive concentrates, product Acontaining about 40% and product A containing about 50% by weight of thephosphosulfurized polyisobutylene.

Treatment of Product A with PbO .--l00 grams of product A were thenstirred with 10 grams of powdered PbO at a temperature of about 190 F.for about 30 hours. The resultant stabilized reaction product,hereinafter referred to as product B, was blended with a solvent refinedmineral lubricating oil (having an S. U. S. viscosity at 210 F. of about45 seconds and hereinafter referred to as the base stock) to form alubricating oil composition containing about 10 vol. percent of productB. This composition was diluted with normal heptane and filtered throughCelite filter aid. The heptane was removed, giving a light-coloredlubricating oil composition of excellent odor characteristics. a

A second lubricating oil composition was prepared 4 using product A.This second composition consisted of about 10 vol. percent of product Ain the base stock. These two compositions had the following properties:

1 The lead acetate test is an effective test for determining thestability as to 1123 evolution of compositions containingsulfur-containing organic materials. This test is carried out asfollows: 800 cc. of the oil composltion are placed in a l-quart bottleand heated at 120F. for one hour. Then a piece of paper moistened withsaturated lead acetate solution is exposed to the blend for a period of5 minutes. The resultant lead sultide stain is rated for its intensity,a rating of 10 being a dark stain with a trace of silvery overlay, arating oi 0 being no stain, and a rating of 10+ being a stain withconsiderable silvery overlay.

It will be noted that the method of the present invention is exceedinglyeffective in stabilizing a sulfur-containing organic material such asphosphosulfurized polyisobutylene. More specifically, it will be notedthat the oil composition containing product B of the present inventionhad a 0 rating in the lead acetate test whereas the oil compositioncontaining product A had a rating of 10+ in the lead acetate test.

Example 11 Product A was stabilized, in accordance with the prescutinvention, utilizing varying proportions of powdered PbO and varyingreaction times to produce stabilized additives as shown below.

1 The lead acetate test was carried out in this example in the followingmanner: The treated product was blended with the base oil to term acomposition of 10 weight percent of the treated product and 90 weightpercent of the base oil. The resultant composition was then rated forE28 evolution as described in Example I.

It will be noted that the evolution of hydrogen sulfide from product Awas reduced by treating it with PbO, in accordance with the presentinvention. When reaction times of 12 hours or greater were employed,there was no detectable evolution of H 8 from the treated product in thelead acetate test.

Example III In this example, product A was blended with the base stockto prepare compositions containing about 10 wt. percent of product A inthe base stock. Portions of this composition were treated with powderedPhD, at several different reaction temperatures to prepare stabilizedcompositions as shown below.

TABLE up k 1 Stabilization reaction carried out with a blend of weightpercent of product A in the base stock.

2 The lead acetate test in this example was carried out as described inExample I.

It will be noted that the evolution of H 8 from the compositionscontaining product A was substantially reduced by treating thecompositions with PhD, in accordance with the present invention.

When the stabilized products, particularly the stabilizedphosphosulfurized hydrocarbons, of the present invention are employed inlubricating oils, they are generally added in proportions of about 0.1to about 10.0% and preferably about 1.0 to about 6.0%, based on thetotal composition. The proportions giving the best results will varysomewhat according to the nature of the additive and the specificpurpose which the lubricant is to serve in a given case. For commercialpurposes, it is convenient to prepare concentrated oil solutions inwhich the amount of the stabilized additive in the composition rangesfrom to 75% by weight, and to transport and store them in such form. Inpreparing a lubricating oil composition for use as a crankcaselubricant, the additive concentrate is merely blended with the base oilin the required amount.

The products of the present invention may be employed not only inordinary hydrocarbon lubricating oils but also in the heavy duty type oflubricating oils which have been compounded with such detergent typeadditives as metal soaps, metal petroleum sulfonates, metal phenates,metal alcoholates, metal alkyl phenol sulfides, metal organo phosphates,phosphites, thiophosphates, and thiophosphites, metal xanthates andthioxanthates, metal thiocarbamates, and the like. Other types ofadditives, such as phenols and phenol sulfides, may also be present.

The lubricating oil base stock used in the compositions of thisinvention may be straight mineral lubricating oils or distillatesderived from parafiinic, naphthenic, asphaltic or mixed base crudes, or,if desired, various blended oils may be employed as well as residuals,particularly those from which asphaltic constituents have been carefullyremoved. The oils may be refined by conventional methods using acid,alkali and/or clay or other agents such as aluminum chloride, or theymay be extracted oils produced by solvent extraction with solvents suchas phenol,

sulfur dioxide, etc. Hydrogenated oils or white oils may be employed aswell as synthetic oils prepared, for example, by the polymerization ofolefins or by the reaction of oxides of carbon with hydrogen or by thehydrogenation of coal or its products. In certain instances crackingcoal tar fractions and coal tar or shale oil distillates may also beused.

Synthetic lubricating oils having a viscosity of at least S. S. U. at100 F. may also be used, such as esters of monobasic acids (e. g. theester of C Oxo alcohol with C Oxo acid; the ester of C Oxo alcohol withoctanoic acid, etc.), esters of dibasic acids (e. g. di-Z-ethyl hexylsebacate, di-nonyl adipate, etc.), esters of glycols (e. g. C Oxo aciddiester of tetraethylene glycol, etc.), complex esters (e. g. thecomplex ester formed by reacting one mole of sebacic acid with two molesof tetraethylene glycol and two moles of Z-ethyl-hexanoic acid; the com--plex ester formed by reacting one mole of tetraethylene glycol with twomoles of sebacic acid and two moles of 2- ethyl hexanol; the complexester formed by reacting together one mole of azelaic acid, one mole oftetraethylene glycol, one mode of C Oxo alcohol, and one mole of C Oxoacid), esters of phosphoric acid (e. g. the ester formed by contactingthree moles of the mono methyl ether of ethylene glycol with one mole ofphosphorus oxychloride, etc.), halocarbon oils (e. g. the polymer ofchlorotrifluoroethylene containing twelve recurring units ofchlorotriflu-oroethylene), alkyl silicates (e. g. methyl polysiloxanes,ethyl polysiloxanes, methyl-phenyl polysiloxanes, ethylphenylpolysiloxanes, etc.), sulfite esters e. g. ester formed by reacting onemole of sulfur oxychloride with two moles of the methyl ether orethylene glycol, etc.), carbonates (e. g. the carbonate formed byreacting C Oxo alcohol with ethyl carbonate to form a half ester andreacting this half ester with tetraethylene glycol), mercaptals (e. g.the mercaptal formed by reacting 2- ethyl hexyl mercaptan withformaldehyde), formals (e. g. the formal formed by reacting C Oxoalcohol with formaldehyde), polyglycol type synthetic oils (e. g. thecompound formed by condensing butyl alcohol with fourteen units ofpropylene oxide, etc.), or mixtures of any of the above in anyproportions. Also, mixtures of these synthetic oils and mineral oils inany proportions may be employed. Also, for special applications, animal,vegetable or fish oils or their hydrogenated or voltolized products maybe employed in admixture with the synthetic and/or mineral oils.

For the best results the base stock chosen should normally be an oilwhich with the new additive present gives the optimum performance in theservice contemplated. However, since one advantage of the additives isthat their use also makes feasible the employment of less satisfactorymineral oils, no strict rule can be laid down for the choice of the basestock. The additives are normally suificiently soluble in the basestock, but in some cases auxiliary solvent agents may be used. Thelubricating oils will usually range from about 40 to 150 seconds(Saybolt) viscosity at 210 F. The viscosity index may range from 0 to oreven higher.

Other agents than those which have been mentioned may be present in theoil composition, such as dyes, pour point depressants, heat thickenedfatty oils, sulfurized fatty oils, sludge dispersers, antioxidants,thickeners, viscosity index improvers, oiliness agents, resins, rubber,olefin polymers, and the like. Assisting agents which are particularlydesirable as plasticizers and defoamers are the higher alcohols havingpreferably 8 to 20 carbon atoms, e. g. cctyl alcohol, lauryl alcohol,stearyl alcohol, and the like.

In addition to being employed in lubricants, the additives of thepresent invention may also be used in other mineral oil products such asmotor fuels, hydraulic fluids, torque converter fluids, cutting oils,flushing oils, turbine oils, transformer oils, industrial oils, processoils, and the like, and generally as useful additives in oleaginousproducts. They may also be used in gear lubricants, greases and otherproducts containing lubricating oils as ingredients.

What is claimed is: I

1. An odor stabilized organic product obtained by treating a phosphorussulfide treated olefin polymer with Pb0 at an elevated temperature inthe range of 80 to 400 F. for a time in the range of 8 to 24 hours.

2. A stabilized organic product obtained by treating a phosphorussulfide treated olefin polymer with about 5 to 30% by weight of PbO at atemperature of about to 350 F. for about 8 to 24 hours.

3. A stabilized organic product obtained by treating a P 5 treatedpolyisobutylene having a molecular Weight of about 500 to 2,000 withabout 10 to 20% by weight of PbO at about 300 F. for about 12 to 16hours.

4. A method for reducing the evolution of hydrogen sulfide from aphosphorus sulfide treated olefin polymer which comprises treating saidphosphorus sulfide treated polymer with about 5 to 30% by weight offinely divided PbO at a temperature of about 150 to 350 F. for about 8to 24 hours.

5. A method for reducing the evolution of hydrogen sulfide from 21 P 8treated polyisobutylene having a molecular weight of about 500 to 2,000which comprises treating said P 8 treated polyisobutylene with about 10to 20% by weight of finely divided PbO at about 300 F. for about 12 to16 hours, and removing unreacted PhD; from the resultant reactionmixture.

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References Cited in the file of this patent UNITED STATES PATENTSMusselman Dec. 11,

1. AN ODOR STABILIZED ORGANIC PRODUCT OBTAINED BY TREATING A PHOSPHORUSSULFIDE TREATED OLEFIN POLYMER WITH PBO2 AT AN ELEVATED TEMPERATURE INTHE RANGE OF 80* TO 400*F. FOR A TIME IN THE RANGE OF 8 TO 24 HOURS. 4.A METHOD FOR REDUCING THE EVOLUTION OF HYDROGEN SULFIDE FROM APHOSPHORUS SULFIDE TREATED OLEFIN POLYMER WHICH COMPRISES TREATING SAIDPHOSPHORUS SULFIDE TREATED POLYMER WITH ABOUT 5 TO 30% BY WEIGHT OFFINELY DIVIDED PBO2 AT A TEMPERATURE OF ABOUT 150* TO 350*F. FOR ABOUT 8TO 24 HOURS.